The demilitarized zone in Idlib isn’t a a political solution; the biggest threat to its success is designated terrorist groups

Rebel groups in Syria have withdrawn most of their heavy weapons from a planned demilitarized zone in the country’s northwest, local activists and the Turkish Ministry of Defense said Wednesday, a move that could forestall an offense by the Assad regime, but falls short of a lasting political settlement in the area.

Russia and Turkey agreed last month to create a buffer zone between opposition and government forces in Idlib province in an attempt to avert a fight that the U.S. and the United Nations have warned would cause...